GAZA, July 31 (Reuters) - An Israeli air strike has killed a Hamas military commander and rocket maker in the Gaza Strip, the Islamist group that rules the Palestinian territory said on Saturday.

Issa Batran was killed by a missile that hit his caravan in the central Gaza Strip. Israel launched air strikes against targets in Gaza on Friday after a rocket fired from the enclave exploded in the city of Ashkelon.

The air strikes also hit a training camp in Gaza City used by Hamas and smuggling tunnels along Gaza's southern border with Egypt. Several people were wounded by debris in Gaza City.

Hamas said Batran was a rocket maker and the head of its military wing in the central Gaza Strip. The militant group has a rocket arsenal of crude, homemade projectiles and longer-range rockets smuggled in through tunnels under the border with Egypt.

Israel carried out the air strikes after militants in Gaza fired a rocket into Ashkelon on Israel's Mediterranean coast, blowing out the windows of an apartment block and damaging parked cars in a residential area.

No one was injured by the blast, which police said was caused by a 122mm, Chinese-made Grad rocket. But the attack ended over a year of calm for the Israeli city closest to Gaza.

It was the most serious attack on Ashkelon, which has a population of 125,000 and lies on the coast about 12 km (7 miles) north of the Gaza Strip, since Israel ended a three-week military offensive in Gaza in January 2009.